The present disclosure relates generally to the field of motor vehicle brake systems. To be more precise, a sensor assembly for use with a master cylinder of such a brake system is described.
It has already been known for a long time to provide the master cylinder with one or more sensors. For example, the hydraulic pressure prevailing in the master cylinder is a frequently interesting quantity, and for this reason many master cylinders are equipped with a hydraulic pressure sensor. The hydraulic pressure in the master cylinder determined by a sensor can be used to detect the driver input. Furthermore, the vacuum in a vacuum brake booster can be calculated from the master cylinder pressure via a model and hence the operability of the booster determined.
In DE 10 2004 013 191 A, it is proposed to provide in the master cylinder a vacuum region communicating with a vacuum chamber of a vacuum brake booster, and to arrange a vacuum sensor in this vacuum region of the master cylinder. A particular configuration provides for integrating the vacuum sensor with a position sensor of a stop light switch in a sensor assembly and for providing the entire sensor assembly in the vacuum region of the master cylinder.
The sensor assembly known from DE 10 2004 013 191 A comprises a finger-like carrier element, at the tip of which the vacuum sensor and the position sensor are accommodated. For positioning the sensors in the vacuum region of the master cylinder, the carrier element with the sensors accommodated at the front is passed through a channel formed in the master cylinder and opening into the vacuum region.
It has turned out that a vacuum sensor involves considerable cost. For this reason, it is desirable to dispense with the vacuum sensor, at least in low-cost vehicles. Separately from this, it has been found that a travel sensor for determining the brake pedal travel is also frequently installed in addition to the position sensor. This travel sensor may be installed at different places in the region of the brake pedal and requires dedicated mounting and cabling solutions.